Conventional loudspeakers produce audible sounds by displacing air via the movement of a diaphragm. Specifically, the diaphragm is attached to a voice coil former and moves under the control of a voice coil through which electric current associated with the sounds to be reproduced is driven. The voice coil is disposed in an annular air gap defined by a pole assembly. The pole assembly includes a permanent magnet that provides radial flux in the air gap. Lead wires provide the electric current to the voice coil which interacts with this flux to provide axial forces on the voice coil and voice coil former which displace the voice coil, former, and the attached diaphragm. The displacement or movement of the voice coil and former is controlled by the magnitude and direction of current in the coil and the resulting axial forces.
Typically, loudspeaker lead wires are routed from the voice coils along the voice coil former, and either through or beneath the diaphragm to an input terminal board connector attached to a basket. The lead wires are generally single strand wires connected to the voice coil which are then attached to flexible wires. The flexible wires are typically heavier than the single strand voice coil wire and are designed to provide additional flexibility intended to accommodate movement of the loudspeaker components during operation. The voice coil wires are affixed to the voice coil former and routed along the former to a location above a spider and apex of the diaphragm where the wires are spliced to the flexible wires. The flexible wires are typically routed along the diaphragm, through an aperture or hole therein, and terminated at the input terminal board connector. In other embodiments, the flexible wires are routed in a space between the spider and diaphragm eliminating the need to pass through the diaphragm, or along or embedded in the spider.
In each of these loudspeaker systems, however, the repetitive movement of the lead wires in association with the voice coil former and diaphragm can cause failures in the lead wires and reduce the quality of the loudspeaker performance. For example, bending and changing the geometry of the lead wires can contribute to premature failure due to fatigue or short circuiting between lead wires and/or other loudspeaker components. Additionally, undesirable noise created through contact between the lead wires and other loudspeaker components, such as the diaphragm, can negatively impact loudspeaker performance.
It has come to our attention that these shortcomings in present loudspeaker design are exacerbated by the effect of the lead wires own mass. The farther the mass is away from a center axis of the voice coil, the more the mass resists the changes of direction that the voice coil and diaphragm are attempting to make. Thus, an important aspect of the present invention is to substantially reduce, if not eliminate, the effect of the lead wires mass in contributing to premature failure and reducing the quality of loudspeaker performance by properly supporting, directing and routing the lead wires.